Here’s a simple-looking age puzzle that can easily catch you off guard.
When I was 6 years old, my sister was half my age. That means she was 3 years old at the time.
Now, I am 70 years old. The important part is that the age difference between us has never changed.
When I was 6 and she was 3, the difference was 3 years.
So, if I am now 70, my sister must be:
70 − 3 = 67
The Answer
My sister is 67 years old.
The trick is that she is not still half my age today. She was half my age when I was 6. Since then, we have both grown older by the same number of years.